package com.wangyu.utils;

import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 线程池管理
 */
public class ThreadPoolManager {

    public static ExecutorService defaultCachedThreadPool() {
        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                60L, TimeUnit.SECONDS,
                new SynchronousQueue<>(),
                DefaultThreadFactory.createDefault());
    }

    /**
     * 默认的线程工厂
     */
    private static class DefaultThreadFactory implements ThreadFactory {
        private static final AtomicInteger POOL_NUMBER = new AtomicInteger(1);
        private final ThreadGroup group;
        private final AtomicInteger threadNumber = new AtomicInteger(1);
        private final String namePrefix;

        private DefaultThreadFactory() {
            SecurityManager s = System.getSecurityManager();
            group = (s != null) ? s.getThreadGroup() :
                    Thread.currentThread().getThreadGroup();
            namePrefix = "pool-" +
                    POOL_NUMBER.getAndIncrement() +
                    "-thread-";
        }

        private static DefaultThreadFactory createDefault() {
            return new DefaultThreadFactory();
        }

        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(group, r,
                    namePrefix + threadNumber.getAndIncrement(),
                    0);
            if (t.isDaemon()) {
                t.setDaemon(false);
            }
            if (t.getPriority() != Thread.NORM_PRIORITY) {
                t.setPriority(Thread.NORM_PRIORITY);
            }
            return t;
        }
    }
}
